Van De Walker et al in U.S. Pat. No. 3,827,856 discloses a method and apparatus for mass-manufacturing elongated hollow plastic objects, such as covers for electronic thermometer probes, and ball point pens having inserts at the ends thereof. The inserts are automatically loaded, by vibrating them into pockets and then lifting them out of the pockets into suction tubes which pass through a horizontal transfer plate into nests in a vertical transfer plate. Vacuum is employed to maintain the inserts in the nests during movement of the vertical transfer plate to positions adjacent the distal ends of the hollow core pins through which air is sucked. The vacuum in the vertical transfer plate is then converted to pressure to cause the inserts to fly across the air gaps to the core pin ends, following which the inserts are maintained on such ends by suction. The mold is then closed to cause the inserts to engage spring-biased plungers, following which the plastic is injected.
Sample et al in U.S. Pat. No. 2,094,823 discloses a method and an apparatus for suspending an insert into a mold cavity by partial vacuum.
These methods and apparatus use a vacuum source and vacuum distribution lines, which increase their initial and maintenance costs and burden the operator and production schedules. There is a long standing need for an economical and efficient device to transfer inserts into the insert receiving cavities of a mold.